fix for issue #2675: search feature should not search on line numbers and headers

[tdtrung17693]

It fixes #2675

Currently, less will perform the search on all the content that is written on its STDIN. To make it ignore the headers and the line numbers, less, from version 600, has added 2 new options:

• --header to set the headers (filename, file size, and panel text)
• --no-search-headers to ignore those headers.

So, I will use those 2 options to make the search work correctly.

Btw, as I said above, this fix is only applicable for less version from 600 and above because those options only existed from that version.

[sharkdp]

Thank you very much — this looks great! Didn't know less had those new features. Do you think it would be possible to write (integration) tests for? I think we mock pager calls in some other tests as well. We could do something similar and check that the mocked less pager is called with the correct offsets.

[tdtrung17693]

Ok. Let me try that.